Flash actionscript 3: proportional image resizing

There is always a moment in a flash developer’s life where he want’s to resize images. For example to create a thumbnail, or just a resized image for your image gallery.

the point is you’d like to resize your images proportional of course, so you won’t get a crappy result. It’s no biggie but I wrote a class in as3 wich resizes the bitmap you like and returns the result.

-UPDATED-

you can download the class HERE. and here’s an example of how you could use it

I’ll explain how you can use the class:

Let’s say you have a few images in a container and you’d like them all to fit in a bounding box with a maximum width and height , 100 px for example. Of course you’d like to resize them proportional. You can use the static class ResizeImage and just make a call to the resizeIt function. Just make sure to assign a few parameters.
ResizeImage.resizeIt(obj,100,100);

Just assign the object you’d like to resize, and give a value for the maximum width and height. The class will resize your object, and in stead of returning another bitmap, your object is resized directly!

For those who are interested here is some explanation about how the class handles the proportional resizing:

first we calculate our ratio, to make sure we can recalculate the width and height proportional

var r:Number;//ratio
r = b.height/b.width;//calculation ratio

With a simple if loop we check if the width of the image is bigger than the max width you want, if so then we set the width to the max value and recalculate the height proportional

if (b.width>maxW) {
b.width = maxW;
b.height = Math.round(b.width*r);
}
After the height is updated we check if this is bigger than the max height you want, if so then we set the height to the max value and recalculate the width proportional.
if (b.height>maxH) {
b.height = maxH;
b.width = Math.round(b.height/r);
}